Now, I have about twenty per hand and can change the number of delays, change different parameters, the delays to the modulations and so forth. I developed the EIS over the time period that I was just talking about [1991].

That change happened about 1991. It was not possible to transfer the Expanded Instrument System to the computer until then, when 16-bit recording became available.

After a long section of the glass playing, you'll hear an instrumental sound emerge from some undisclosed location. There'll be a lot of mystery about the sound, I think.

I had invented my own system, my own way of making electronic music at the San Francisco Tape Music Centre, and I was using what is now referred to as a classical electronic music studio, consisting of tube oscillators and patch bays. There were no mixers or synthesizers. So I managed to figure out how to make the oscillators sing. I used a tape delay system using two tape recorders and stringing the tape between the two tape machines and being able to configure the tracks coming back in different ways.

That's software in the States that I helped to develop. It enables people with disabilities to improvise.

The San Francisco Tape Music Centre was a kind of collective non-profit that my friends and I got started so that we could pool our equipment and make tape music.

I'm currently very impressed with the level of understanding and of interest in listening that I experience wherever I go. That motivates me to dig deeper into what I've been doing all of this time, to find new ways and also to get over the thought that it's not happening.